Being a teacher in a learner-centered proficiency based system can mean some big changes. One of the biggest changes in thinking to work through involves taking a step back from working with targets at a particular level, to working with a range of targets within the measurement topic. Remember, a Measurement Topic is a series of related targets arranged in a progression from simple to complex. Measurement Topics do not necessarily have one target, or level, per grade. Nor do Measurement Topics necessarily always make sense to begin when students enter the school system in preK or Kindergarten